Is this because of the following:
For tables that do not have the parallel DML itl invariant property (tables created before Oracle Database release 9.2 or tables that were created with the COMPATIBLE initialization parameter set to less than 9.2), the degree of parallelism (DOP) equals the number of partitions or subpartitions. That means that, if the table is not partitioned, the query runs in serial. To see what tables do not have this property, issue the following statement:
SELECT u.name, o.name FROM obj$ o, tab$ t, user$ u
WHERE o.obj# = t.obj# AND o.owner# = u.user#
AND bitand(t.property,536870912) != 536870912;
will recreating the table really help this and does the PCTFREE and INITRANS play a part
If my DOP is 6 does it help to recreate my table with initrans set to a value of 6 and above?
1) Of course this is a possibility. It is up to you to know whether your table fits what is described in the documentation (you copied that text from http://download.oracle.com/docs/cd/E14072_01/server.112/e10837/parallel.htm#VLDBG1531, didn't you?). Note that there are other situations that lead to a serial execution... e.g. triggers, foreign keys and object columns.
2) If the condition specified in the documentation is met, recreating the table should fix it. I do not see how PCTFREE and INITRANS might help.
3) With a PDML you want to have a single process working on a block. Hence, it's not necessary to have several ITLs.